Gabriela is 8 years older than Omar. Two years ago, Gabriela was 5 times as old as Omar. How old is Omar now?
Answer: We can use the given information to write down two equations that describe the ages of Gabriela and Omar. Let Gabriela's current age be $g$ and Omar's current age be $o$ The information in the first sentence can be expressed in the following equation: $g = o + 8$ Two years ago, Gabriela was $g - 2$ years old, and Omar was $o - 2$ years old. The information in the second sentence can be expressed in the following equation: $g - 2 = 5(o - 2)$ Now we have two independent equations, and we can solve for our two unknowns. Because we are looking for $o$ , it might be easiest to use our first equation for $g$ and substitute it into our second equation. Our first equation is: $g = o + 8$ . Substituting this into our second equation, we get the equation: $(o + 8)$ $-$ $2 = 5(o - 2)$ which combines the information about $o$ from both of our original equations. Simplifying both sides of this equation, we get: $o + 6 = 5 o - 10$ Solving for $o$ , we get: $4 o = 16$ $o = 4$.